Stupid Thought

This happens more often than I'd like to admit.

I'm grocery shopping.  I've made my way through all the aisles, checking prices and figuring out what I'm going to eat next, and "do I already have some of that?" and so on, and then I get to the checkout counter and I'm watching the cashier ring up my items, and I think, even if just for a second;

"...this stuff costs money?"